Boring mill



June 2, 1953 I w. K.-MILLHOLLAND, JR 2,640,377

BORING MILL Filed Aug. 1, 1951 6 Sheets-Sheet} lo -INVENTOR, I \MLL/AM K MLLHQLLAND JR. Ev M 0. mm

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June 2, 1953 w. K. MILLHOLLAND, JR 2,640,377

BORING MILL Filed Aug. 1', 1951 6 Sheets-Sheet} INVENTOR, no \A/lLL/AM K. MILLHOLLAND JP.

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June 1953 w. K. MILLHOLLAND, JR 2,640,377

BORING MILL Filed Aug. 1, 1951 6 Shegts-Shel 4 INVENTOR, WILL/AM K. MILLHOLLAND JR. 15y W a. mu

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June 1953 w. K. MILLHOLLAND, JR 2,640,377

BORING MILL .F'iled Aug. 1, 1951 .6 Sheets-Shaetf5' ll l0 INVENTOR, WIL IAM A. M/LLHoLLA/vp JR.

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w. K. MILLHOLLAND, JR 4 77 June 2, 1953 BORING MILL Filed Aug. 1, 1951 6' Sheets-Sheet 6 INVE TOR, WILL/AM K. MILLHOLLAND JR.

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M t 6- E w .9 3 3 mm I m: MN m 5 i; 3 3 i Patented June 2, 1953 UNITED STATES PATENT OFFICE 2 ,640,377 BORING Mitt- William K. Millholiand, Jr, Indianapolis; Ind. A henian August 1, 195i, seriei Ne. sate- 3' @lainis.

This invention relates to a-boririe' Ifnilland par} ticularly to the head of a boring zilill which be hand adjusted into ps'iti'oi-is' along ways or a bed. The invention particularly resides the unique structure Which permits arotary drive of the tool boring bar and also which permits automatic feed longitudinally of the" bar withinpredetermined limits. The longitudinal feed is eontroned' automatically to very precise limits, this control feature being embodied ina strue ture forming a particular partof the invention.

The particular construction of the boring mill which enters iri-th the eresent invention promotes a; very quick up for any particular operation and permits extremely high degree of adcur'acv ixr'the longitudinal travel of the bar. The machine may he set for making a fast out followed by a slow out and may be automati'eally advanced and contradted in respect to the bar or within the lan of operation Fii-rthermore the particular construction p81- avery rugged design so that the machine will not only be free of undue vibration, but will remain usable and accurate over an extremely long period: of time.

"Fli'es'e' and many other objects and advantages oi the invention: will become;- ainparent to those skilled in the art-inthe following description of one particular form or the inventionasillustrated in the acc'ornp-anying'- drawings; inwhich L is a view in side elevationof a structure embodying the invention;

Fig, 2 is a view in r'ear end elevation;

Fig.- 3 a=-view in front end elevation;

Fi'g.- 4a, is a view in: vertical centralqseetion through therear endportion of the machine;

Fig.4bis a view in side elevation and central section of the upper portion of the machine as a continuationof the view shown'inFig. 4w;-

Fig.-5-isa=detai-l in'endelevation of-the miorom eteradjustment for longitudinal feeding;

Fig. 6- is a-view in side elevation ofthe structure shownin-Fig. f); I

Fig. '7 is a, detail in horizontal section on the line 1-1 in Fig. 1; and u H M Fig: 8- is a-vertieal section on the line 8-'8- in A-base member 10- has formed onthe upper side thereof a bar housing. It and continuing from the back side of the housing l l" is a tubular housing l2, in turn' carrying on the rear end a gear drive housing-i3. I

' A bar has an drive sleef' el'5 fitted; over its forward endeportion andthrough which sleeve it the bar l4 may travel longitudinally on a horizontal axis. This sleeve i5 is provided witha bear-ingbushing [6- fitted into its forward end portion;- Eixternally' of thesleeve lt' on its forward'portionthere fitted; a-pair of radial and 2 tlirdstroller hearings l1 and It, in: turn carries tr the bar hoiising n; Fig} it. The sleeve it extends rearwa-rdiy alon the bar It; and in its rear portionea ies a bearing bii'shing 2t gii Whieh the bar it may travei gitudina y." tau bearing 2'! is shown g carried externally 0f the sleeve arid fitted within the housing i I so that the'bar" it may turn with the sleeve It on the anti-friction bearings i'iyiii; and 21.

Sinet-he bar Mr is free to be carried longitudi naliy through the sleeve I5, the bearings I? and it are so' fitted in the housing H as to restrain the sleeve 45' from longitudinal travel relative to the housing H.-

The sleeve I5 is slotted on dianiet-rical sides forwardly of the bearing 2! to provide the slots 19 and tea, through which keys'22 and 23' engage slidi-ngly within keyways; 2d and 2-5 extending longitudinally along the bar 54 on diamtricaliy Qpposed sides thereof. Each of these keys 2'2 and 2% is formed to have ears 2'6 and; 21 extending o'verinlapping relation onto the sleeve [5 at the ends of their respeetive slots 19 and [941, arid the keys a-re' fixed to the sleeve by means, of the cap screws 28 and 29 extending through the ears and screw-threadedly engaging in the sleeve [5. Thomas a: matter of precaution; these sews it; and- 29 are heldagainst lqosening dr theme by means of a wire?!) which is passed throug their heads and twisted toge of b? their eii'd'sfi f assidicategt in Fig; e; f Ih e verses lfie-Htol the keys 2-2 and 23 issueh each instance that the lgeys n slidingly within the iivws ysf 24 and 2 when the ears 2 and 2? are sea-ted on the sleeve 15. y I P o A. drive fii'dtidf 321 is s rainers the rest or the base f0, and this the. motor revolves the on horizontal I I leng thof the housih'g l2} and fi 'e'eh tle's'cepes over" the its-swam ei'rd sort eschew shaft 35" This shaftfiis rew oliibly 'darrie dby" the bealringsfih and-3 mounted on the rear and front sides'respeetivelv of the housing:- I 3; Fig-i 4w;-

Within the housing ['2 and forward of: the hearing: 3? there is armit generally designated-by the numeraltfiz This ut- 38*; hasan outer hous with a rear eylindrical end portion .40- ir lin': whichisfittegl escrow-threaded sleeve sleeve 4! isfixed'aeainst rotati I I housingfi byarifsuithblehiie h ifi'sho'w'ii asb'v a blobk'fl' sele'etitlii 1s see-sesame -shaft 35. against the outer end of the hub 60' so as to 1: retain the disc 59 in fixed longitudinal position .nonithe shaft 35. By means of this construction, the plate 62 may be shifted rearwardly out of contact with the disc 59, that is the plate 62 with the teeth 43 which are formed circumferentially around a rear end of the sleeve 4|, Figs. 4a, '7, and 8. This block 42 is secured in the selected position by means of a screw 44, screw-threadedly engaging in the cylindrical portion 49.

From the rear cylindrical portion 48, the housing 39 flares forwardly and outwardly to engage over the outer raceway of a thrust bearing 45 which is mounted on the rear end of the bar l4 and secured thereon against longitudinal displacement. An annular ring 46 extends over the forward side of the bearing 45 and is attached to the front end of the housing 38 by any suitable means such as by the screws 4'1. Thus the housing 39 is prevented from longitudinal travel independently of travel of the bar M. In other words, the housing 39 is carried in 1ongitudinal directions with the travel of the bar l4. A front bushing 48 is secured in the housing 39 between the front end of the bushing 4| and the rear end of the bar l4, this front bushing 46 being fixed to the housing by any suitable means such as by the screws 49. This front bushing 49 is screw threaded to receive the shaft 35 screw threadedly therethrough. By reason of the fact that the bushing 4| and the bushing 49 are in two separate parts, the rear bushing 4| has to be aligned with the bushing 48 which is fixed in the housin 39, and that is the reason for the use of the block 42 selectively engaging in the teeth 43 in order to position the bushing 4| at the proper degree of revolutions. This also permits taking up wear in the threads by turning the bushing 4| relative to the bushing 48.

In order to hold the nut 38 against rotation about the axis of the bar |4, there is provided a holding block 58 which extends in a sliding fit horizontally outwardly through a slot provided along the housing I21. This block, Fig. '7, has its inner end mortised into the housing 39 and is attached and held in fixed engagement with the housing 39 by means of a pair of screws 52 and 53.

A hydraulic motor 54, Fig. 4a, is mounted against the forward face and upper portion of the housing |3. This motor has a drive shaft 55 extending into the housing |3 to carry a pinion gear 56 in constant mesh with an idler gear 5'] in turn constantly meshed with a driven gear 58 that is fixed on the shaft 35 between the bearings 36 and 31. Thus, when the motor 54 is operating, the shaft 35 is revolved to cause the nut 38 to travel therealong, and in turn to cause the bar M to travel likewise.

The shaft 35 extends rearwardly beyond the hearing 36 to carry thereon in fixed manner outside of the housing 3 a disc 59. The disc 59 being fixed to the shaft 35 revolves therewith. The disc 59 has a hub 60 extending rearwardly therefrom around the shaft 35, and a compression spring 6| is carried therearound to abut by one end against a plate .62 which fits by a hub portion 63 around the hub 60 and normally bears against the rear face of the disc 59. The other end of the spring 6| bears against a nut 64 which screw-threadedly engages around the The nut 64 is normally turned up is shifted against The plate 62 has an annular forwardly extending flange 65 which telescopes over the periphery of the plate 59. The plate 59 is provided with a plurality of closely spaced transversely positioned teeth 66 entirely around its circumference. The inside of the flange 65 is likewise provided with matching teeth to engage and fit snugly between the teeth 66, Fig. 5. By retracting the plate 62 from the disc 59, the plate 62 may be revolved in relation to the disc 56 and then return to bear thereagainst with the teeth therebetween interengaging in different relations. That is, the plate 62 may be selectively positioned circumferentially around the plate 59 in any selected angular position. As a means for readily determining the angular relationship between the plate 62 and the disc 59, the peripheral face .66 of the plate 62 is provided with indexing marks 61 spaced apart circumferentially at distances corresponding to the spacing of the teeth 65. Then fixed on the side of the housin I3 is a plate 68 which is provided with indexing marks 61a. Thus the relative positions of the lines 67 and BM may be observed in making the relative adjustments between the plate 62 and the disc 59. For convenience in the initial set up of a job, the shaft 35 is provided with an end 69, herein shown as squared so that a wrench or crank may be detachably engaged therewith as a means for revolving the shaft 35. A cover 79 is fitted over the back face of the housing |3 to enclose the nut 64 and the plate 62.

Mounted above the plate 62 is a slide vertically guided and normally carried to a lowermost position by means of a compression spring 12 bearing between an upper stop plate 13 and the top side of the slide 1|, Fig. 2. A solenoid I4 is mounted to one side of the cross slide H and has its armature l5 rockably engaged to a lever 16 pivoted on the cap screw 71, to have an outer free end presented underneath a nut 18 carried on the upper end of the stem 19 which extends upwardly from the slide through the upper plate 13. When energized, the solenoid I4 rocks the lever 76 to lift the slide 1 I A bell crank lever 89 is pivoted on the slide H to have an arm 8| extend normally downwardly to be in the path of a stop 82 which is fixed on the plate 62 to extend into the path of that arm. The other arm 83 of the crank extends substantially horizontally (when the slide 1| is in its lowermost position) over the top of a roller 84 which is mounted in the end of the arm 85 in turn connected to a switch 86. V

When the slide H is dropped downwardly, the lower end will be in the path of the stop 82 so as to stop the turning of the plate 62 instantly (the motor 54 having been automatically stopped) and also the switch arm 85 has been operated to affect a circuit entering into the overall control system.

The block 58 which is attached to the nut 38 and which extends through the slot 5| extends beyond the wall of the housing 12 a distance, Fig. '7, and has fixed on its outer end a timing control bar 88. This bar 88, Fig. 1, extends horizontally along the housing l2 to have its forward end guided in a sliding manner between the up.- per and lower guide blocks 89 and 99 respectively. The control bar 88 is spaced outwardly, laterally from a switch mounting box 9|. On the bar'88, there are secured a number of stops, herein shown as four in number and designated bythe numerals 92, 93, 94, and 95. These stops are adjustably secured along the bar 88 by bolts 96,

Fig. 7, which extends through the stops and through the central horizontal slot 91 which extends through the major length of the bar 8 3. Into the paths of these stops 93, 94, and 95 there are carried operating arms 86, 97, $8, and S9 of respective electric switches [80, liil, Hi2, and H13. These switches are mounted on the box 9|.

The box 9! is used simply to contain the wires leading from those respective switches, and from that box 9!, the wires lead into the main control box I04 mounted thereabove. The control system as is operated by these various limit switches IUD-I03 inclusive does not constitute any part of the present invention per se, and hence the control circuits are not shown or described. It is sufficient to state that these cir cuits operate to control valves controlling flow of fluids to and from the hydraulic motor 54, in the usual and well known manner.

The entire mill is mounted preferably to slide along ways I05 and H35, Fig. 2, and the mill is rapidly carried to the approximate position desired by means of turning a side shaft 157 by any suitable means such as by a crank (not shown), this crank in turn turning a spur gear H18 which is in constant mesh with a rack bar I89 held stationary by the bed I It.

In operation, in the original set-up for the production job, the entire mill is adjusted along the ways I05 and 186 to the approximate position. Then by preliminary travel of the bar M, the stops 92-95 are adjusted along the bar 88 to be in the correct positions for operation of the respective switches Hill-m3 for the required control. The final micrometer adjustment for depth of the cut, that is effected by the advance of the bar it, is made through the relative interconnection between the plate 52 and the disk 59. This interadjustment as above described is made so that when the proper limit switch, one of the switches lfil3lll3, is operated, the solenoid 74 will respond thereto, to drop the slide 1'! into the path of the abutment 82 and instantaneously stop the rotation of the shaft 35, also in stantaneously causing the crank 2!] to actuate the arm 85 of the switch 86 which in turn stops travel of the hydraulic motor 54. That is the switch 86 is a motor stop switch and the solenoid i4 is a slide release device so that there is precise stoppage of rotation of the shaft 34 to effect the depth of a out within a very close tolerance.

Advantage is taken of the fact that the nut 38 does not revolve in respect to the shaft 35 or the bore I3, and that a lubricating pipe H2 may be carried through the slot 5| to engage the side of the nut so that lubrication may be fed from a lubricator H3 through the pipe H2 through the passageway H4 into the central portion of the nut between the members 4| and 48.

While I have herein shown and described my invention in the one particular form, it is obvious that structural variations may be employed without departing from the spirit of the invention, and I therefore do not desire to be limited to that precise form beyond the limitations which may be imposed by the following claims.

I claim:

1. In a boring mill, the combination of a housing; a bar revolubly and longitudinally shiftable in respect to the housing; motor means revolving the bar; a screw-shaft for longitudinally shifting the bar; motor means revolving said shaft; a disk fixed to said shaft to revolve therewith; a plate longitudinally slidable along said shaft; spring means yieldingly urging said plate toward said disk; an annular flange on said plate telescoping over the periphery of said disk, said flange and said periphery being respectively toothed for selective circumferential interengagement maintained by said spring; an abutment carried by and externally of said plate; a slide carried by said housing to be reciprocable into and out of the path ofsaid abutment; means yieldingly retaining the slide in said path; electro-magnet means normally energized to withhold said slide from said path in opposition to said spring; a screw-shaft motor means control switch arm; a rocker member pivotally mounted on said slide to have one portion in the path of said arm and another portion in the path of said abutment to shift said arm upon abutment travel thereagainst to stop said shaft motor means; and means actuated by longitudinal travel of said bar to deenergize said electro-magnet means to have said slide stop instantaneously revolution of said screw shaft by said abutment striking said slide.

2. For controlling precise limits of travel of a boring tool in a boring mill, the combination of a tool carrying bar; a motor for revolving the bar; a screw-shaft interconnecting with the bar to set up longitudinal travel thereof; a motor driving said shaft; an abutment carried by said shaft adjustably positioned circumferentially therearound; a slide carried by said mill guided to reciprocate into and out of the path of said abutment; yielding means normally maintaining said slide to be in said path; a bar revolving motor control switch arm; a rocker carried by said slide to be in the path of both said abutment and said arm when the slide is moved into said abutment path, said arm being biased by said abutment through said rocker to a motor deenergized position; electro-magnet means normally energized for shifting said slide in opposition to said yielding means to hold said slide and said rocker out of the path of said abutment; and switch 1 means actuated by longitudinal travel of said bar to deenergize said electro-magnet means.

3. A boring mill control comprising a tool bar; a motor to revolve the bar; a screw-shaft to shift the bar longitudinally; a second motor to turn said screw-shaft; an abutment carried by said shaft; a control actuated by a predetermined longitudinal travel of said bar; a member normally directed into the path of said abutment to stop turn of said shaft; normally energized electro-magnetic means withholding said member from said path; said control deenergizing said electro-magnetic means upon said shaft travel to permit said member to stop turning of said shaft; a shaft drive motor control arm; a member carried by said first member when in said abutment path to be also in said abutment path and in the path of said arm to arrest said shaft motor from turning of the shaft.

WILLIAM K. MILLHOLLAND, JR.

References Cited in the file of this patent UNITED STATES PATENTS Number 

